JPS58148491A - Method of producing metal foil laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This invention relates to a method for manufacturing a metal foil-clad laminate.

The following method has been developed as a continuous forming method for metal foil-clad laminates used for printed wiring circuit boards and the like. That is, unsaturated polyester resin.

Unsaturated resins with unsaturated bonds, such as diallylturate resins and vinyl ester am, are converted into vinyl monomers (crosslinking agents).
etc., and further add a polymerization initiator to make an unsaturated resin liquid (varnish). This is impregnated into a base material such as a band of paper or glass cloth, and the unsaturated resin-impregnated base material is continuously rolled up. .

Next, multiple layers of this resin-impregnated base material are layered while being transferred,
Furthermore, a laminate is continuously produced by overlapping a metal foil such as a Kll-shaped copper foil and, if necessary, a delamination film, etc., while transferring them. This method then continuously produces a metal foil-clad laminate by heating the laminate under no pressure while transferring it using a heating furnace (non-pressure forming). This method is
The production efficiency is high because the method does not involve putting the laminate in a press machine and applying heat and pressure, but instead heats and hardens the laminate under no pressure to continuously manufacture the laminate.
In addition, in the production of unsaturated resin varnish, since the varnish is made by diluting the unsaturated resin with a crosslinking agent rather than diluting it with a layering agent, there is no need to use a layering agent, resulting in resource savings, etc. But it's excellent.

However, if ordinary adhesives such as epoxy resin or phenol Itil are used to bond copper foil,
Conventionally, it has been extremely difficult to fully satisfy both the peel strength and the static beer strength. This is because the following phenomena are observed. In other words, when a copper foil coated with a B-stage adhesive is laminated onto a base material impregnated with an A-stage unsaturated resin, peeling occurs between the unsaturated resin and the adhesive when heated.
Low static peel strength. On the other hand, a product in which a copper foil coated with an A-stage adhesive is laminated on a base material impregnated with an A-stage unsaturated resin has low beer strength at room temperature. In short, there has never been an adhesive that can perform both hot and normal conditions at the same time.

In view of these circumstances, as a result of intensive research, the inventors used vinyl ester resin as an adhesive, applied it to the copper foil, set it as a B stage in a certain range, and superimposed it on the substrate material. It has been found that by using the following formula, it is possible to satisfy both the beer strength and the beer strength when heated.

Generally, vinyl ester resin fil is an unsaturated carbon # (methacrylic acid, ac 1) in the epoxy group of the epoxy resin.
Curing is done by reacting double bonds in the presence of -(-oxide) to make it two-dimensional, similar to ordinary unsaturated polyester resins. Like unsaturated vinyl ester resin, it is a radical polymerization type, so polymerization is inhibited on surfaces that come in contact with air.Therefore, when vinyl ester resin is applied to copper foil and dried in a drying oven, the temperature and time are suddenly increased. Moderate selection (resin composition.

(depending on the crosslinking agent, initiator, etc.), the surface in contact with the copper foil is cured, and the surface exposed to air can be left uncured. After lamination, the vinyl ester resin on the uncured surface (Ifi in contact with the unsaturated resin-impregnated base material) mixes with the unsaturated resin impregnated into the base material, and is cured and integrated by heating. On the other hand, the vinyl ester resin 11jI on the surface in contact with the copper foil exhibits the adhesive strength inherent to the vinyl ester resin to the steel foil without mixing with the unsaturated resin impregnated into the base material.

Vinyl ester resin adhesives are extremely effective as shown above, but they are difficult to use. That is, when the adhesive thickness is 60 mm, the beer strength is significantly reduced. In that case, it is necessary to apply the adhesive to a thickness greater than that, but when it becomes thicker, the curing shrinkage of the adhesive increases significantly, and the resulting laminate becomes negative when processed into a printed wiring board. Large warpage occurs, which poses a practical problem.

In order to solve these problems, the inventors conducted further experiments and research. As a result, vinyl ester tree ll1
This invention was completed after learning that the problem could be solved by applying the I-adhesive only to the substrate material side.

That is, the present invention is a method for obtaining a metal foil-clad laminate by overlapping a metal foil on a substrate material made of an unsaturated 11111-impregnated base material, laying down a strip-shaped laminate, and curing it under no-pressure F while transferring it. A method for manufacturing a metal foil-clad laminate is provided, which is characterized in that a vinyl ester resin adhesive is selected as the adhesive to be interposed between the substrate material and the metal IO, and this is applied only to the solid side of the substrate. The summary and now. This will be explained in detail above.

FIG. 1 is an explanatory diagram illustrating the steps of the method for manufacturing a metal foil-clad laminate according to the present invention. Base materials 2 are supplied from a plurality of rolls. As the base material 2, four known materials such as paper, glass, cloth, etc. are used. , unsaturated ** is supplied from the nozzle 4 to each base material 2 as it passes through the guide rolls 3.3 in turn, impregnating the cloth. Unsaturated polyester resin, diallylphthalate resin, vinyl ester 11a [i] is diluted with a crosslinking agent such as a vinyl monomer such as styrene, and a polymerization initiator is added. In addition, a publicly known resin may be used. This resin may be impregnated by a method such as a dipping method. The resin-impregnated base material 21 impregnated with an unsaturated resin is a pair of upper and lower squeeze rolls 5, 5b and are superimposed on each other to form a substrate material (11 layers) 6. However, the substrate material may consist of just one resin-impregnated base material. An adhesive is applied to the overlapping surfaces of the metal foils, but prior to this, it is preferable to squeeze out as much of the excess resin as possible from the impregnated resin.

This is because K makes the beer even stronger.

This diaphragm) hanger is normally a Nuquiz roll 5a.

5b, but it may be done by a separately provided squeezing means (not shown) such as a squeezing roll.

The adhesive is applied to the substrate material 6 by rolling.

Spraying is carried out using a known application means 7. The adhesive is mainly composed of vinyl ester w fat, and contains a thermal polymerization initiator such as benzoyl peroxide, t-butyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, etc. Contains, if necessary, a crosslinking agent such as styrene, hinyltoluene, divinylbenzene, diallyl phthalate, ethylene glycol dimethacrylate, trimethylolpropane-8-propane trimethacrylate, and polystyrene.

Polyvinyl acetate, polyalkyl methacrylate.

It is preferable to use a material containing a low shrinkage agent such as a saturated bo-13 ester obtained from a saturated dibasic acid and a glycol. The curing accelerator added to this is naphthenic acid. Polymerization inhibitors such as manganese naphthenate and co-octenoate include noidowaquinone. Catechol, p-benzoquinone, etc. are good. In the adhesive there is also hydrated alumina as a filler.

Clay, Merck, calcium carbonate, methyl silicate, etc. may also be added. Adhesives may also be applied using suitable solvents such as acetone, MEK, toluene, and the like. The adhesive coating thickness is K.
Although it is not necessarily fixed at 111N, it is preferably 50# or less, and more preferably 20 to 35μ.

The substrate material 6 coated with the adhesive is then fed into a pair of upper and lower laminating rolls 8m and 8b, and a steel foil wafer metal foil 9 and a release film 10 are superimposed on the upper and lower surfaces of the laminating rolls to form a strip-shaped laminate. It becomes 11.

The laminate 11 enters the heating furnace 12 and is heated and hardened as it moves through the furnace, forming a metal foil-clad laminate 11'. The laminate may be cured by means other than heating.

In short, it is sufficient if the curing is performed under no pressure.

A double-sided metal foil-clad laminate can be obtained by applying a vinyl ester** adhesive to the lower surface of the substrate material 6 and overlapping a metal foil 9 instead of the release film 1O.

The manufacturing method of the metal foil-clad laminate according to the present invention uses vinyl ester* with good adhesive properties between the substrate material and the metal foil.
*Because the adhesive is interposed and the adhesive is applied only to the substrate material side, it has sufficient normal and static beer strength even with a small adhesive thickness, and also has a negative strength. It is possible to produce metal foil-clad laminates with less warpage. First, there is no step of applying adhesive to the metal foil, and there is no need for an adhesive pre-curing oven, which simplifies the process and equipment.

Next, examples will be described together with comparative examples.

[Examples 1 to 8, Comparative Examples 1 to 3] Kraft paper with a thickness of 10 mils (0,254 mm)
Manufactured by AI Valve Co., Ltd., HL-10) For K, unsaturated ay
t'Reester Tree It (manufactured by Dainippon Ink Co., Ltd., FG-10
4) B as a polymerization initiator? Five resin-impregnated base materials impregnated with 1 weight of 0 are passed through a laminating roll with a narrowed clearance and overlapped while squeezing the excess unsaturated polyester resin to form a strip-shaped substrate material. And so.

A vinyl ester resin adhesive having the formulation shown in Table 1 was coated only on the substrate material in the Examples to the thickness shown in Table 1, and in the Comparative Example it was coated only on the steel foil to the thickness shown in Table 1. The adhesive applied to the copper foil was dried at 190° C. for 4 minutes.

Layer the steel foil on the substrate material using a laminating roll, and heat the resulting strip-shaped laminate in a heating oven (100°C x 10 minutes +
A single-sided copper-clad laminate was obtained.

The normal and static beer strength and warpage of the copper-clad laminates obtained in the Examples and Comparative Examples are as shown in the llirl table, and overall, the Examples are superior to the Comparative Examples. was.

(Hereafter, remaining white)

[Brief explanation of drawings]

FIG. 1 is a process explanatory diagram showing an embodiment of the present invention. 2'...Resin-impregnated base material 4..., nozzle 515b...
・Squeeze roll 6...Substrate material 8a, 8b,...
Laminating roll 9...Metal foil 11...Stacked pigeon body
11'...Metal foil clad laminate Patent applicant Matsushita Electric Works Co., Ltd.

Claims (1)

[Claims] (1) A method for obtaining a metal foil-clad laminate by superimposing a metal foil on a substrate material made of an unsaturated resin-impregnated base material to obtain a strip-shaped laminate, and curing it under no pressure while transferring it, the method comprising:
A metal foil lamination method characterized in that a vinyl ester resin and adhesive is selected as an adhesive to be interposed between the substrate material and the metal foil, and this is applied only to the substrate material. (ri) A method for producing a metal foil-clad laminate according to claim 1, wherein the coating thickness of the adhesive is less than or equal to 100%. A method for manufacturing a metal w1 layered laminate according to claim 1 or 2.